The objective of this project is to further develop, miniaturize, and extend the new Phenotype MicroArray (PM) platform technology (1-3) and then utilize this improved technology to genomically analyze biological pathways and gene function in the model eucaryotic microorganism Saccharomyces cerevisiae. The steps will be 1) development of miniaturized, more efficient, and lower cost second generation technology, 2) characterization of all of S. cerevisiae's known genes, 3) construction of a computerized, database integrating this genomic and phenotypic information, and 4) retrospective evaluation and modifications of PM technology to make it more useful and comprehensive. Phase I will primarily be concerned with step 1 of this process. [unreadable] [unreadable] A major need in current research is to understand, in depth, the function of large numbers of genes. Multiple, independent approaches are needed. Biolog's new PM technology provides a new approach in which one gene at a time is tested by phenotypic assay under thousands of cellular conditions. Testing of large numbers of genes is accomplished by testing a comprehensive collection of isogenic microbial strains with single gene knockouts or other alterations in an automated high-throughput program. With this approach, we can rapidly and efficiently build up a storehouse of information about gene function that will be extremely valuable to biological researchers. [unreadable] [unreadable]